and biological, orb it has no basis in reality at all. and that's the wrong way to think about it. >> it is a social construct, but there are real world consequences for it. people died because of their race, even though it is something that people constructed for -- >> yeah, and of course that certain ethnic differences that you can see. you can mostly guess whether someone has ancestors in asia or ancestors in africa or ancesto in europe. the way in which we think about the difference wean races is socially constructed. and that's what's relevant in this context. in the united states, tradit traditionally -- but the most important has been whether somebody is black or somebody is not black. that will determine whether somebody might have been enslaved. that determines whether somebody's rights might have been violated in the most extreme ways. but there is lots of different contexts in the world in different ways of thinking about